The cello column is a cylindrical shape with a radius of about 12 millimeters, usually made of pine wood. The normal position is roughly behind the left foot of the qin horse (i.e. on the side of the high pitched string), about 7-8 millimeters away from the sound hole. The quality, length, and placement of the wooden column have a significant impact on the tone and volume. Due to climate change and vibration during transportation, if the sound column shows obvious skewness or falls, it must be adjusted and reinstalled in a timely manner, otherwise it will affect the normal vibration of the instrument and damage it. Some cellos have a column that immediately falls down when the strings are loosened, which is due to the improper production of the column. In this situation, you can replace the column with a slightly longer one. If you feel that the string vibration is a bit tight and the tone is relatively hard, it may be due to the long column or the position being close to the guitar horse. You can adjust it by visual and auditory inspection.